27,508 research outputs found
[To Flower Mission workers].
No full textCaption title. Author from last p.; Cover title: Flower Mission Department, W.W.C.T.U.; Ferguson, J.A. Australia, 18876; Electronic reproduction. Canberra, A.C.T. : National Library of Australia, 2010.Flower Mission Department, W.W.C.T.
Flowers through insect eyes: the contribution of pollinator vision to the evolution of flower colour
No full textPhDFlowers’ colours are an essential element of their ability to attract visits from
pollinators. However, the colours as they appear to human observers can differ
substantially from their appearance to insect pollinators, and so it is essential to consider
pollinator vision in any study of the ecology of flower colour.
In this thesis I describe how I have overseen the development of an online database to
provide accurate information on floral spectral reflectance measured without human
observational bias. This resource allows a more accurate consideration of flower colours
in future studies, and permits investigations of flower colours within and across
habitats. Using the records in this database, I analysed flowers from two European
habitats for spatial or temporal changes, modelling the colours according to insect visual
perception. I discovered that the insect-colour composition of the plant communities
does not change either along an altitudinal gradient or throughout the year. These novel
and ecologically-relevant analyses contradict previous observational studies, but support
the theory of a pollination “market” in which flowers compete for pollinator visitation.
I then describe my experimental investigations into the visual capabilities of two
pollinators and how this may relate to what colours of flowers they visit. Firstly I study
the foraging behaviour of bees under spatially inconsistent illumination and how this
impacts on their choice behaviour. I revealed patchy light can have measurable effects
on bee foraging behaviour: they intentionally choose familiar over unfamiliar
illumination, which may impact on the flowers they visit in complex natural
environments. Secondly, I detail the new evidence for a red-sensitive photoreceptor in
South African monkey beetles, a major pollinator in a habitat containing many longwavelength-
reflecting flowers, which are not classically “attractive” to bees.
Throughout this thesis, I explore how pollinator vision has shaped the evolution of
flower colours in different contexts.Biotechnology and Biological Science Research Council.
Royal Botanical Gardens Kew (BBS/S/L-2005/12155A
Recommended from our members
Long-Term Monitoring at East and West Flower Garden Banks National Marine Sanctuary, 2011-2012. Volume I, Technical Report; Vol II, Appendixes.
No full textSummary describing the work completed at NOAA Flower Garden Banks National Marine Sanctuary for 'Long-Term Monitoring at East and West Flower Garden Banks National Marine Sanctuary (2011-2012).' It includes background information on the project funding and sponsorship, goals, methodology, and findings
Preference and performance of western flower thrips
No full textDifferences in performance on, and preference for, different plant parts were studied on cucumber plants. On these plants thrips are often most abundant on the youngest plant parts. This suggests that the youngest leaves are most suitable for western flower thrips. We assessed if differences in suitability of leaves of different age could explain the distribution of thrips on cucumber plants. Evidence was obtained for a correlation between preference and performance on cucumber leaves of different age. Differences in performance on, and preference for, different host plant species were studied with selected isofemale lines. Thrips from these isofemale lines showed differences in performance on different host plant species. It was assessed whether these differences in performance were correlated with differences in preference. No clear evidence was obtained for correlations between preference and performance on different host plant specie
International Flower Networks: Transparency and Risks in Marketing Channel Choice
No full textTwo thirds of Kenyan cut flowers are marketed through Dutch flower auctions, while the remainder is marketed directly to retailers. Auctions do not restrict the volumes marketed; however price determination is based on a spot market. A Transaction Cost approach is used to investigate the differences in marketing costs between the channels. The results suggest that there are no differences between the channels in terms of uncertainty about prices, finding buyers or transparency of quality standards. Auction growers pay a higher marketing fee but they have significantly fewer office employees and flower varieties compared to growers who market directly.Transaction Costs, Auction, Flowers, Kenya, Netherlands, Agribusiness, International Relations/Trade,
The evolution of flower size and flowering behaviour in plants: The role of pollination and pre-dispersal seed predation
No full textThis thesis describes research into the effects of insect mediated pollination, and pre-dispersal
seed predation, in common species of Asteraceae, varying both between and throughout
growing seasons, and suggests that these exert selective pressures influencing the evolutuion
of both inflorescence size and flowering phenology. Changes in the level of infestation of capitula (by tephritid fly larvae) and in capitulum size
were monitored by twice-weekly collections from populations of common species of
Asteraceae over the course of five years’ flowering, in 2002 to 2006. Seed counts of drying
flower heads were made over the course of the research, identifying levels of seed set in both
uninfested and infested flower heads. A mathematical model was created to investigate the
extended influence of the parameters measured in the field, and predict their influence on
longer term evolution of Asteraceae. Two flower species exhibited both significant levels of infestation, and significant differences
in fecundity. In Leucanthemum vulgare, infestation (by Tephritis neesii) peaked mid-season at
all sites. In Centaurea nigra, infestation (by gall-forming Urophora spp) peaked mid-season,
infestation (by non-gall forming Chaetostomella cylindrica) was lowest in mid-season. In
both species the probability of attack increased with capitulum size, despite a consistent
decline in capitulum size through the season. This suggests that the insects choose larger
capitula from those available at each stage, regardless of absolute size. The presence of
infestation showed a consistent reduction in the level of fecundity in both species. These
findings suggest a selective effect. The mathematical model provides evidence of the long term effects, up to 1000 generations,
of variations in both pollination success, and pre-dispersal seed predation, and suggests that
the values measured in the field are consistent with selective pressures that contribute to the
evolution of both flower size and phenology
Anti-Allergic Cromones Inhibit Histamine and Eicosanoid Release from Activated Human and Murine Mast Cells by Releasing Annexin A1
No full textPMCID: PMC3601088This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
"Defining best practice...? Elementary my dear researcher."
No full textIn this brief but engaging article, the author ruminates on the political nature of research and on the problems this poses for East Asian Medicine, and points to the fact that the thorny business of defining best (or at least 'good enough') practice is of central importance here. He concludes by offering a richly simple model - based on the Five Phases (wu xing) - for defining what best practice is.<br/
Funerary Flower Bouquets
No full textThree small bouquets and a flower cross are displayed on a table with a card containing the message "Deepest Sympathy, Class '92.
- …
